Table 2 Physiological studies looking at the effect of stress on DNA damage and tumor development
From: Stress and breast cancer: from epidemiology to molecular biology
Study | Study focus | Study design | Subjects | Results |
|---|---|---|---|---|
Kiecolt-Glaser and colleagues [104] | DNA damage | DNA-repair capacity in lymphocytes in response to X-ray irradiation | Distressed vs. nondistressed psychiatric patients | Lower DNA repair capacity in distressed individuals |
Glaser and colleagues [105] | DNA damage | DNA repair capacity during period of stress | Medical students during examination | Increase in DNA repair capacity during period of stress, possibly as initial response to increased DNA damage |
Cohen and colleagues [106] | DNA damage | Levels of O6-methylguanine-methyltransferase following stress exposure | Stressed vs. control rats | Levels of DNA repair enzyme are reduced in stressed rats |
Fischman and colleagues [107] | DNA damage | Rate of sister chromatid exchanges in response to γ-irradiation, mitomycin-C in the presence of environmental stressors | Stressed vs. control rats | Increase in sister chromatid exchanges in stressed rats; increased susceptibility to mutagenesis |
Sacharczuk and colleagues [108] | DNA damage | Rate of DNA mutation occurrence Oxidative damage | Stressed vs. control rats | Increased rate of DNA mutation occurrence in stressed rats |
Adachi and colleagues [109] | DNA damage | Rate of DNA mutation occurrence Oxidative damage | Stressed vs. control rats | Increased rate of DNA mutation occurrence in stressed rats |
Weinberg and Emerman [73] | Tumor development | Tumor growth in response to acute daily novelty stress | Socially isolated vs. group-housed male mice | Increased tumor growth in socially isolated animals |
Grimm and colleagues [74] | Tumor development | Tumor growth in response to change in housing conditions | Mice switched from group to individual housing vs. individual to group housing | Increased tumor growth rate in mice switched from group to individual housing |
Hermes and colleagues [75] | Tumor development | Life-time risk of mammary tumor incidence, tumor growth rate in response to social isolation | Socially isolated vs. group-housed female rats | Increased risk for developing at least one malignant tumor; increased tumor growth; hyperactive response to future stressors; sustained changes in HPA-axis signaling |
Williams and colleagues [76] | Tumor development | Tumor incidence, tumor size in response to social isolation | Socially isolated vs. group-housed mice | Increased tumor incidence; increased tumor size; higher number of poorly differentiated adenocarcinomas in socially isolated animals; increased HPA-axis reactivity to additional stress; no permanent changes in baseline corticosterone; global changes in gene expression |